How does the common rail diesel system work?

The high-pressure pump places fuel under pressure and delivers it to a common pipeline used as a pressure storage tank. The pressure is regulated through an electronic control valve to maintain the pressure required by the electronic control unit in the public pipeline.

Then the fuel reaches the injector and occupies two compartments, one above the atomizer needle and one below the atomizer needle. Two opposing forces cancel out each other, and due to a small spring, the needle remains closed. The upper compartment, known as the control room, has a vent regulated by a solenoid or piezoelectric control valve.

When the electronic control unit opens the valve, the compartment above the needle is emptied, and the pressure in the lower compartment controls the opening of the needle valve and begins the injection process in the combustion chamber. This process only ends the valve when the command is interrupted; The pressure accumulation in the control room caused the atomization needle to close.